1. Field of the Invention
Embodiments disclosed herein relate to the use of a panel(s) for germicidal sterilization. Certain embodiments disclosed herein relate to a portable mat with LEDs (light-emitting diodes) for germicidal sterilization.
2. Description of the Relevant Art
Medical equipment and spaces are continually in need of sterilization to remove germs and create a clean and safe environment for patient treatment. Current sterilization methods often include the use of chemical cleansing methods. For example, bleach, Hibiclens®, iodine, and/or isopropyl alcohol are often used to chemically clean medical equipment and medical spaces. Chemical solutions, however, can be messy and difficult to work with in addition to being environmentally unfriendly. Human tissue may also be damaged by some chemical solutions.
In 1877, Dr. Arthur Downes and Dr. Thomas Blunt made the discovery that sunlight, which includes ultraviolet (UV) light, has a germicidal effect on bacteria. Continuous research since that discovery has shown that specifically UVB and UVC light are capable of destroying 99% of bacteria and viruses. UV lights have been used as a method of decontamination (sterilization) in limited applications since the 1950s. In the 1990s, near-UV and blue light exposure was found to sufficiently damage the surface of numerous types of bacteria to render the bacteria inactive.
In 2005, ongoing research at Strathclyde University showed that near-UV LED (light-emitting diode) light exposure at 405 nm was sufficient to produce similar results to previous UV light research. UVC and UVB light, however, may cause damage to human tissue and cannot be used (under most conditions) directly on human tissue. Blue and near-UV LEDs may also be fragile and difficult to deploy, especially at portable or remote medical spaces.
Heat may also be used to sterilize surfaces. For example, heating the surface or the surrounding air around the surface may sufficiently heat microbials (bacteria) until they die. The temperatures required to destroy most types of bacteria, however, are temperatures at which human tissue (or other organic material) is damaged or decomposes. In some cases, heat may be used in combination with chemical solutions (such as those described above).
Strathclyde University developed a UV ceiling module that utilizes LED diodes comingled with other types of LEDs. The comingling provides scotopic values of near-UV (violet) with actual photopic values being significantly higher. The mixing of the light does not produce a functional average wavelength (e.g., 200 nm+400 nm=600 nm, etc.) but rather a mix of wavelengths (e.g., 200 nm comingled with 600 nm). Germicidal efficiency may be determined by the intensity (lux) and spectral wavelength (nm). Because intensity is a product of the number of devices producing a specific wavelength of light, the comingling produced fewer lux than necessary at the appropriate wavelength in the UV ceiling module. The low germicidal efficacy, in addition to other problems, kept the UV ceiling module from being an accepted product.
Ionizing lamps (e.g., UV ionizing lamps) have also been used to provide germicidal sterilization. These lamps, however, often use low voltage current (e.g., household 120 V current) that passes through exposed wires to “ionize” the immediate environment. The wavelength of the UV lights integrated into these devices is inappropriate to provide any germicidal effect. These lights are typically considered as more gimmick than functional for germicidal sterilization.
UVC LED deployments are another design that has been used to attempt germicidal sterilization. UVC light, as discussed above, however, may adversely affect human tissue exposed to the UVC light. For example, direct contact with UVC light for prolonged periods may cause bums and/or cellular changes consistent with certain types of cancer. UVC does, however, have high germicidal sterilization efficacy so is a usable solution for sterilization when no direct human contact is needed (e.g., uses other than physical evaluation or treatment of a patient). Thus, there remains a need for a germicidal device that is non-chemical, non-toxic, effective, easily deployable (e.g., portable), and safe for use in a variety of medical spaces. Such a device may be especially useful for temporary medical facilities used in military engagements, natural disaster scenarios, or other short term medical deployment situations.